It is oftentimes desirable to reclose a bag once it has been opened, particularly if the bag contains a food product which would spoil or become stale if the bag was allowed to remain open. It would also be beneficial for the bag to be sealed by the manufacturer, food processor, or the like (after the bag is filled with a marketable product) with a tamper resistant device which could subsequently be utilized to reclose the bag (and hence protect the bag's contents from spoilage) once it has been opened by a purchaser. In such a situation, the purchaser would benefit from visual assurances that the bag had not been opened prior to its being purchased (i.e., so that the purchaser is assured that no-one has tampered with or adulterated the contents of the bag).
Various contrivances have been proposed in the past in order to accomplish bag-closure functions. For example, U.S. Pat. No. 3,001,254 to Schuum discloses a bag closure device which is comprised of a web having a projecting rib and an opening formed on its respective halves. A disc with an annular groove, and a ring are provided at respective opposite ends of the web. In use, the web is folded onto itself (as is more easily permitted by means of a hinge part) such that the ring catches in the annular groove. The rib, in turn penetrates into the opening so that the bag therebetween is forced at least partially through the latter (i.e., so that it "bulges" through the opening). In such a manner, the device of Schuum U.S. Pat. No. 3,001,254 closes a bag.
A divided circular handle for carrying mesh bags is disclosed in U.S. Pat. No. Re. 23,629 to Henriksen. The handle of Henriksen U.S. Pat. No. Re. 23,629 is comprised of two halves which define respective arcuate tongues slidably matable with one another. In use, the bag is attached to the lower parts of each of the halves, and one of the tongues is slid under the other tongue. Thus, the bag is dependently supported by the handle when the halves are mated with one another but is capable of being opened when the two halves are separated.
Lucke et al in U.S. Pat. No. 829,661 disclose a bag lock which is comprised of a strap whose ends include a recessed keeper (having an annular flange) and a cylindrical case lock (having bolts). When the case lock is pressed into the keeper, the bolts will snap behind the flange thereby securing the lock and keeper one to the other.
A number of bendable bag closure devices are also known in the art, one such device being shown in U.S. Pat. No. 2,700,805 to Bedford, Jr. Usually, bag closure devices of this type will be formed from a bendable material (e.g., metal ribbon) so that it is capable of being manually deformed into and out of gripping relationship with a bag top so as to respectively close and open the same.
As the reader will appreciate, there still exists a need in this art for a bag closure device which not only is capable of reclosing the bag once it has been opened, but which is also capable of being used by a product manufacturer in the first instance to close the bag prior to being shipped to the consumer market. A need is also present for such a bag closure device which provides the consumer purchaser with a visual indication of the integrity of the bag's contents--that is, an indication that the bag has not been opened prior to purchase. The present invention is directed towards such needs.
According to this invention, a bag closure device is provided with a pair of annular (e.g., circular ring-shaped) closure members which are nestable with one another. In the preferred embodiment, one of the closure members is generally L-shaped in cross-sectional configuration while the other closure member is generally U-shaped in cross-sectional configuration. The L-shaped one of the closure members is thus provided with an upright flange, and a shelf which extends outwardly from the flange towards the other U-shaped closure member and defines an annular concave seating surface. The U-shaped closure member, on the other hand, is provided with an opposing pair of upright, spaced-apart wall segments which are integrally joined at their bottoms to define an annular convex engagement surface.
When the two closure members are nested, the convex engagement surface will be positioned in an annularly adjacent relationship to the concave seating surface so as to capture a portion of a flexible bag therebetween. In such a manner, the bag is closed by means of the device of this invention.
The two closure members are most preferably joined to one another by an integral hinge which facilitates foldable movement of the closure members relative to one another into and out of their nested relationship.
The nesting of the two closure members may be enhanced by an annular lip formed on a terminal end of the shelf of the L-shaped closure member. The lip bears against one of the upright wall segments of the U-shaped closure members and thus serves to frictionally resist separation of the two closure members from their nested relationship.
Locking capability and/or visual tamper evidence is optionally provided with the device of this invention by means of, for example, an upright stake (associated with one of the closure members) and a tab and aperture member (associated with the other closure member). The stake may be provided with an integral enlarged head (i.e., enlarged as compared to the diameter of the aperture) so that it can be press-fitted through the aperture and releasably lock the two closure members one to another while they are in their nested relationship. The stake and integral enlarged head may be, for example, similar to the structure disclosed in U.S. Pat. No. 4,441,233 issued to Allan W. Swift on Apr. 10, 1984 (the entire content of which is expressly incorporated by reference herein).
Visual tamper evidence is most conveniently established by at least partially melting the terminal end portion of the stake which extends through and beyond the aperture defined in the tab to an extent where the stake and tab are melded to one another thereby forming a tamper evident "seal". In such a situation, any previous opening of the bag will immediately visibly be apparent by virtue of the separation and/or abnormal distortion of the seal formed between the stake and tab.
Other features and advantages of this invention will become more clear to the reader after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.